Sure, a window AC has a thermostat to regulate itself, but it doesn't recognize when no one is at home, so it can't lower and raise temperatures automatically to reduce your electric charges. And you can't turn it down remotely. (Furthermore, turning it off when you leave the house won't do the trick: it simply means cranking it up even more when you return)

So Tado, a Munich-based company, has hit on the idea of turning dumb AC units into smart devices by linking them to your home network and the Internet. Tado's $199 Smart AC Control is a flat waffle-shaped remote control that has Wi-Fi and infrared built in so that it connects to the Web and can control any AC that uses a standard IR remote.

Essentially, Tado wants to do for air-conditioners what Nest did for thermostats. But rather than replacing a product, Tado wants to work with existing ACs on the market. At the moment, there are dozens of more advanced AC units that you can choose from a list on the app when you set it up. Or, if your air-conditioning unit has a less sophisticated remote control (one without an LCD display), the installation software will walk you through teaching the Tado remote to turn your AC on and off and to raise and lower the temperature. (With models that use an LCD remote, you get more advanced control of economy modes, fan speeds, etc.)

Gadget fans will find this all vaguely familiar. It's the approach taken by one of the most successful companies in the accessory space, Logitech. Its Harmony universal remote control has built up an extraordinary database of IR remote control codes over many years and now can control thousands of different consumer electronics products. Tado isn't there yet, but it shows a lot of promise.

In my test case, I used a more modest air conditioner, but I was easily able to turn the unit on and reset the temperature remotely, either using the app (Android and iOS) or via a Web browser.

If you change the temperature using the wall-mountable remote control, it will also be reflected in the app and online (and vice versa). Logging into your account online you'll find a Nest-like, crisply designed interface with salutation ("Good Morning"), indoor and outdoor temperatures, humidity level readings inside, and controls and schedule settings.

In my case, on/off, temperature and manual or automatic settings were available. There's also a "smart schedule" setting that lets you set temperatures for when you're sleeping or away from home. The system knows when you're away by tracking your location via the Tado app on your smartphone. The company has even considered the comfort of more than one person in the home, so you can add roommates who can also trigger the AC automatically according to their location.

Tado has done an excellent job with the interface, software, and overall design (the touch sensitive controller with LEDs that wink on and off makes it unobtrusive). But I do have a couple of caveats. If you set the Tado remote controller too close to the AC (it needs to be within line of sight) the controller will think it's cooler in the room than it may actually feel to you and shut off the air conditioning prematurely. Result: you'll feel a little too warm until you turn the temperature setting down lower. The other minor annoyance: When I changed the temperature remotely, warning beeps sounded at home as the controller confirmed its settings and then basically counted down to the new temperature setting (it scared the cats).

There are other technological solutions that also try to reduce air-conditioning bills, but they tend to be more expensive. The $449 Mistbox, for example, sprays water outside your AC to bring cooler air inside and improve efficiency. There's also the $249 Quirky air conditioner that has many of the features Tado's remote control offers but has it all built into the AC (unfortunately, Quirky relies on the problem-plagued Wink app).

In the smart home/Internet of Things space, there are plenty of fatuous ideas and gadgets, but controlling all those in-window ACs cranking out energy makes a lot of sense. Of course, Tado's Smart AC Remote Control would be even more attractive for less money ($100 would be ideal), but even at its current price it can easily pay for itself over a long, sweltering summer.

John R. Quain is a personal tech columnist for FoxNews.com. Follow him on Twitter @jqontech or find more tech coverage at J-Q.com.